15A NCAC 02H .0124      RELIABILITY

All facilities shall provide adequate reliability measures to ensure continued treatment and disinfection where the interruption of such treatment would result in a discharge of insufficient quality to protect the best intended uses of the affected surface waters. The reliability measures shall include the following:

(1)           For new or hydraulically expanding facilities with mechanically operated components, and for any facility that mathematical modeling or other analysis determines would impact surface waters if treatment were interrupted, multiple (dual at a minimum) components such as pumps, chemical feed systems, aeration equipment and disinfection equipment;

(2)           At least one of the following:

(a)           dual or standby power supply on site; or

(b)           approval by the Director that the facility:

(i)            serves a private water distribution system that has automatic shut‑off at power failure and no elevated water storage tanks and has sufficient storage capacity that no potential for overflow exists; or

(ii)           can tolerate septic wastewater due to prolonged detention and would not threaten the best intended uses of the affected waters as a result of power failure; or

(c)           provided that the waters that would be impacted by a power failure are classified as C Waters, a demonstration by the applicant of:

(i)            a history of power reliability that would demonstrate that an alternative power source would not be needed; or

(ii)           other measures would provide comparable assurances that surface waters will not be impacted during power failures;

(3)           For new or hydraulically expanding mechanical facilities, the treatment plant must contain parallel units for components in the liquid line, such as screening, primary sedimentation, biological treatment units, chemical and physical treatment units, clarifiers, disinfection and effluent filters, unless the applicant can demonstrate that this requirement is not necessary to ensure the reliability of one or more unit processes;

(4)           For mechanical facilities with a design capacity equal to or greater than 5.0 MGD and continuous operation, 24 hours per day, seven days per week staffing with each shift staffed by at least one certified wastewater operator unless the applicant can demonstrate that this requirement is not necessary to ensure reliability of its facility;

(5)           For facilities permitted under this Section, the permittee must designate an Operator in Responsible Charge and a back‑up operator as required by the Water Pollution Control System Operators Certification Commission as established in 15A NCAC 08G .0201; and

(6)           The Operator in Responsible Charge, or back‑up operator when appropriate, must operate and visit the facility as required by the Water Pollution Control System Operators Certification Commission as established in 15A NCAC 08G .0200 et seq.

History Note:        Authority G.S. 143‑214.1; 143‑215.1(b); 143‑215.3(a)(1);

Eff. December 1, 1984;

Amended Eff. March 1, 1993; October 1, 1987;

Readopted Eff. May 1, 2020.